The relay protection tester under UHV power can help many power workers conduct various power tests more conveniently.

The main functions are as follows:

Action device transmission device

1. Circuit tester microcomputer environmental protection

When accidents such as wind, snow, lightning strikes, external damage, insulation damage, and external insulation flashover pollution occur during the operation of transmission lines, the relay protection tester can quickly and selectively switch the faulty circuit breaker (switch).

If the fault is non permanent, when the instantaneous fault disappears, the switch is successful and the power supply line is restored to safety. If the fault is permanent and the overlap switch fails, quickly troubleshoot the faulty circuit and ensure that the power supply to the circuit is normal.

2. Overcurrent protection device

The protective device adopts the characteristic that the fault current line of the power grid can significantly affect the increase of current, which refers to the protective control device. When the line tester reaches the environmental protection current set value (starting current) from a fault, the information protection device immediately runs the current. When the circuit breaker trips after a certain set time. We generally divide current protection into: current protection, overcurrent protection, and current direction protection.

Infinite time fast break current protection: Its advantages are simplicity, reliability, and fast operation, but it only protects a portion of the circuit.

Current limiting protection: The protection device itself means a shorter operating time limit, which can not only protect the entire data line but also protect the environment by extending the speed of disconnection.

3. Distance protection device

The reaction can be carried out between the installation of the fault point protection system and the work site where an environmental protection measure (impedance) exists. It has good directionality and is widely used in high-voltage line ring networks. Currently, the widely studied three-stage distance protection information is the distance I, II, and III

4. Zero sequence current protection device

The grounding grid (also known as the high current control system grounding wire) is directly connected to the neutral line. If a single-phase grounding fault occurs, there will be the development of high neutral current lines. It is formed using zero sequence current, and the grounding fault protection environment can be referred to as zero sequence current through protective safety devices. We often use a three-stage approach.

It is to convert the current phase (or power direction) at both ends of the line into a high-frequency data signal, and transmit the signal to the other end in a more environmentally friendly or current phase control method through the high-frequency channel direction.

5. The high-frequency fault protection circuit is not reflected outside the protection range, and the next level and line setting values are not required. There is no time limit, and the protective wire can be removed at any time, which is a rapid fault.

High frequency protection engineering can be divided into two categories based on its frequency locking protection (comparing the protection of the power line at the opposite end) and high-frequency phase loss protection (comparing the protection line across the current phase).

6. Automatic reclosing control device

The device that can automatically reclose with the circuit breaker to trip the circuit breaker is called automatic reclosing.

Automatic reclosing action control device: When the transient fault disappears and a transient fault tripping circuit problem occurs, the automatic reclosing system can quickly reclose the circuit breaker and restore the normal operation of the power supply development line. If a permanent fault occurs between the lines and automatic reclosing fails, the fault analysis line can trip again to quickly eliminate the faulty line and ensure the operation and management of power supply lines for other economic enterprises.